FIG. 6 is a flowchart showing a conventional process of bending a long member. First, a tensile force is applied to a long member in a single uniform manner for a predetermined period of time to draw out the long member in the lengthwise direction (S1, S2: YES), and a bending pressure is applied to the long member to bend the long member into a curved shape in the lengthwise direction thereof after the tensile force is reduced in accordance with the drawn-out amount of the long member (S3, S4, S5).